PARIS – During Fashion Week, most celebrities find themselves running from show to show — but Ansel Elgort spent the morning running up the 1,600-plus stairs to the top of the Eiffel Tower.

“I’ve just been hanging around Paris, and I’ve had a lot of macarons,” he said on Saturday while waiting for the Dior Homme show — his second of the week — to start. “So I ran up and down the stairs, and it was a bit of a workout.”

He’s back to Atlanta shooting the next installment of the Divergent trilogy early Monday morning, so he needed to stay in shape over his break. “It’s good to be able to get away to Paris and have a quick vacation.”

Insurgent sees him reteaming with his The Fault in Our Stars co-star Shailene Woodley.

“It’s been a dream come true. You can never guarantee an audience for your films, so for us to have such an amazing reception, it’s really a privilege,” he said of the massive worldwide hit that has propelled him to his first front row of Paris Fashion Week. “It’s been a bit of a whirlwind.”

He was seated next to rapper Kid Cudi, another Paris Fashion Week virgin.

Cudi at first deflected questions and photo requests, before opening up. “I was trying to, but I know with the blonde hair here I can’t be discreet,” he said pointing to his new lighter locks.

“I’m a fan, and I think people know that about me. I’ve made songs about it. And this is my first show in Paris, so why not come to support a brand I’ve loved for so long and see what the hoopla is all about,” said the self-professed Dior fan. “They’re creative with clothing and like to push the envelope.”

“I fell in love with the denims first — Dior is about the design and the sleek and the edge,” he said, adding: “But I’m always about comfort first.” He chose a good time to attend his first Dior show, as this collection showed looser-cut denim and suits with nautical nods for the spring/summer 2015 collection.

The Dior men’s collection, helmed by Kris Van Assche, also drew design stars, with fellow designers including Chanel’s Karl Lagerfeld and Colombian designer Haider Ackerman embracing for photos in the front row, just down from Balmain’s Olivier Rousteing, as well as models Isabeli Fontana and Candace Swanepoel, both of whom sported wet-look, slicked-back hairstyles.

“It’s an easy go-to when I don’t have a lot of time, and in summer it’s off my face,” said Swanepoel of the messy wet look, which could be confused with the hairstyles of those who had been caught up in the midsummer downpour outside.

On why she and her friend Fontana came to check out the show: “We’re surrounded by women’s fashion all the time, so I like a new perspective — and it never hurts to see some cute boys around.”